title: Secretory phospholipase A2 inhibition attenuates intercellular adhesion molecule-1 expression in human esophageal adenocarcinoma cells.
abstract: BACKGROUND
  Esophageal adenocarcinoma is an aggressive malignancy, with most patients succumbing to metastatic disease. The presence of intercellular adhesion molecule-1 (ICAM-1) in these cancer cells contributes to their metastatic potential. The ICAM-1 production in other cell types is stimulated by the actions of phospholipase enzymes. We hypothesize that inhibition of the enzyme secretory phospholipase A2 (sPLA2), which contributes to the growth potential of normal esophageal mucosa and esophageal cancer cells, may attenuate ICAM-1 production and nuclear factor-kappa beta activation in human esophageal adenocarcinoma cells.
  
  
  METHODS
  The FLO-1 verified human esophageal adenocarcinoma cells were treated with 5-(4-benzyloxyphenyl)-4S-(7-phenylheptanoylamino) pentanoic acid, a specific inhibitor of group IIa sPLA2 (5 μM, 10 μM, and 15 μM doses), followed by tumor necrosis factor-alpha stimulation (20 ng/mL). Cells and medium were collected and analyzed by immunoblotting, flow cytometry, and enzyme-linked immunosorbent assay. Statistical analysis was performed using analysis of variance with the Fisher's least significant difference post-hoc test.
  
  
  RESULTS
  Treatment with sPLA2 inhibitor attenuated total cellular ICAM-1 expression in a dose-dependent manner (p<0.005). Cell-surface and secreted ICAM-1 expression decreased significantly with sPLA2 inhibitor treatment (p<0.001 and p<0.05, respectively). sPLA2 inhibition attenuated nuclear factor-kappa beta activation dose-dependently (p<0.05).
  
  
  CONCLUSIONS
  Esophageal adenocarcinoma has significant metastatic potential, and inhibiting its metastasis would significantly advance the treatment of this disease. We demonstrate here that treatment of human esophageal adenocarcinoma cells with sPLA2 inhibitor attenuates the expression of ICAM-1, a marker of metastatic potential, and nuclear factor-kappa beta activation, suggesting a common pathway between the two. These findings identify inhibition of sPLA2 as a potential therapeutic target for esophageal adenocarcinoma.
authors.affiliation: Department of Surgery, Division of Cardiothoracic Surgery, University of Colorado at Denver and Health Sciences Center, Aurora, Colorado 80045, USA.
authors.forename: Miral R
authors.initials: MR
authors.lastname: Sadaria
authors.forename: Xianzhong
authors.initials: X
authors.lastname: Meng
authors.forename: David A
authors.initials: DA
authors.lastname: Fullerton
authors.forename: T Brett
authors.initials: TB
authors.lastname: Reece
authors.forename: Roopali R
authors.initials: RR
authors.lastname: Shah
authors.forename: Frederick L
authors.initials: FL
authors.lastname: Grover
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Weyant
mesh_terms: D000230:Adenocarcinoma / Q000201:enzymology / Q000556:secondary; D000704:Analysis of Variance; D003470:Culture Media; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D004797:Enzyme-Linked Immunosorbent Assay; D004938:Esophageal Neoplasms / Q000201:enzymology / Q000473:pathology; D005434:Flow Cytometry; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000235:genetics / Q000378:metabolism*; D009362:Neoplasm Metastasis; D054497:Phospholipases A2, Secretory / Q000187:drug effects* / Q000378:metabolism; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
chemical_list: D003470:Culture Media; D004791:Enzyme Inhibitors; D014409:Tumor Necrosis Factor-alpha; D018799:Intercellular Adhesion Molecule-1; D054497:Phospholipases A2, Secretory